With the development of electronic devices, problems have arisen, for example, in that electromagnetic noise emitted from an electronic device causes a failure in other electronic devices, or an electronic device malfunctions due to electromagnetic noise emitted from other electronic devices. Thus, there has been a demand for EMC measures in a process of designing and assembling an electronic device.
Since the electromagnetic noise is blocked by a metal, it may be conceived to hermetically seal an electronic circuit which is a source of generating the electromagnetic noise, for example, within a housing made of a metal. As an example, it may be conceived to install flanges on two metal members (a housing body and a lid) forming a housing, respectively, and overlap and fix the flanges by screws, caulking, rivets, welding or the like (hereinafter, referred to as “connecting elements”).
When the two metal members having the flanges are fixed by the connecting elements such as screws, an attenuation amount of the electromagnetic noise is relative to the widths of the flanges and the arrangement interval (pitch) of the connecting elements. For example, when a frequency is 1,000 MHz, and the arrangement interval of the connecting elements is 7.5 cm, the width of each flange which is required to reduce the electromagnetic noise by 15 dB is about 5 cm.
However, in an electronic device such as a computer, when the flanges each having the width of 5 cm are installed, the size of the electronic device increases, and furthermore, a problem is also caused in view of design.
The following is a reference document.
[Document 1] Japanese Laid-Open Patent Publication No. 2007-067195.